redundancy, update and deletion anomalies
storing SSN, sName pair once for each college

Functional Dependency: SSN -> sName
same SSN always has same sName
should store each SSN’s sName only once

BCNF: if A -> B then A is a key

Decompose: Student(SSN, sName) Apply(SSN, cName)

Multivalued Dependencies and Fourth Normal Form

Apply(SSN, cName, HS)

redundancy, update and deletion anomalies
multiplicative effect: student who applies to X college and attended Y high schools has X*Y tuples in the database
Not addressed by BCNF: no functional dependencies

Multivalued Dependencies SSN ->> cName
Given SSN has every combination of cName with HS
should store each cName and each HS for an SSN once